Age Difference Calculator
Calculate the exact age difference between two people in years, months, and days
Calculate Age Difference
Enter information for both people to calculate their age difference
Famous Age Differences
Charles & Diana
12 years, 7 months, 15 days
Diana was younger
Typical Marriage
0-1 years difference
Most common (33%)
Small Gap
2-3 years difference
Common (20%)
Moderate Gap
4-5 years difference
Less common
Method Comparison
Birth Dates
Most accurate method
Exact down to days
Current Ages
Quick calculation
Good for estimates
Birth Years
Approximate only
±1 year accuracy
Quick Tips
Use birth dates for the most accurate calculation
Add names to personalize the results
Switch between different time units for various perspectives
Get insights about relationship age differences
Understanding Age Differences
Calculation Methods
Our age difference calculator offers three methods, each with different levels of accuracy:
Birth Dates Method
The most accurate method using exact birth dates. Accounts for leap years and varying month lengths.
- • Precise to the day
- • Handles leap years automatically
- • Best for legal/official purposes
Current Ages Method
Quick calculation using current ages. Good for estimates when exact dates aren't available.
- • Fast and simple
- • Supports multiple time units
- • Good for rough calculations
Birth Years Method
Approximate calculation using only birth years. Accuracy varies by ±1 year.
- • Simplest input
- • Historical comparisons
- • Approximate results only
Manual Calculation Example
Example: Diana vs Charles
Diana: July 1, 1961
Charles: November 14, 1948
Step 1: Align to same day (Nov 14, 1961 vs Nov 14, 1948)
Step 2: Years difference: 1961 - 1948 = 13 years
Step 3: But Diana's birthday hadn't passed on Nov 14, so 12 years
Step 4: Months from July to November = 4 months back = 8 months forward from November to July, so 7 months
Step 5: Days from July 1 to November 14 in reverse = 15 days
Result: 12 years, 7 months, 15 days
Age Difference Formula
Simple ages: |age1 - age2|
Birth years: |year1 - year2|
Birth dates: Complex date arithmetic accounting for leap years and month variations
Note: The calculator automatically determines who is older and presents results as positive values with clear labeling.
Age Differences in Relationships
Statistics from US marriage data showing age difference patterns in relationships.